Podrobnosti záznamu

Název
    Tourmaline of the elbaite-dravite series from an elbaite-subtype pegmatite at Bližná, southern Bohemia, Czech Republic
Údaj o odpovědnosti
    Milan Novák, Julie B. Selway, Petr Černý, Frank C. Hawthorne, Luisa Ottolini
Další názvy
    Tourmaline 1997. International Symposium on Tourmaline (Variant.)
Autor
    Černý, Petr
    Hawthorne, Frank C.
    Novák, Milan, 1952-
    Ottolini, Luisa
    Selway, Julie B.
Jazyk
    anglicky
Zdrojový dokument - seriál
    European journal of mineralogy
Svazek/č.
    Vol. 11, no. 3
Strany
    p. 557-568
Rok
    1999
Poznámky
    7 obr., 1 fot., 3 tab., 2 s.bibl.
    Zkr. název ser.: Eur. J. Mineral.
Předmětová skupina
    chemismus minerálů
    mineralogie topografická
    moldanubikum Šumavy
    mramor
    pegmatit
    petrogeneze
    turmalín
Geografické jméno
    Bližná (Český Krumlov)
    ČR-Čechy
Klíčové slovo
    Bližná
    Bohemia
    Czech
    Elbaite-dravite
    Elbaite-subtype
    Pegmatite
    Republic
    Series
    Southern
    Tourmaline
Abstrakt (anglicky)
   he elbaite-subtype pegmatite at Bližná, near Černá v Pošumaví in southern Bohemia, Czech Republic, intrudes dolomite-calcite marble. It can be divided into two distinct units, unit A and unit B, and has a narrow exocontact zone along the edge of the pegmatite. The crystallization sequence of tourmaline from unit A is Ca-rich schorl-elbaite Ca-rich elbaite-schorl-dravite > Mn-rich elbaite > Mn-rich liddicoatite > liddicoatite-elbaite, typical of tourmaline from elbaite-subtype pegmatites. The crystallization sequence of tourmaline from unit B is Na-rich unite > Ca-rich schorl-elbaite-dravite > Ca-rich Mg-bearing elbaite > (Ca, Mn)-rich elbaite > Mn-rich liddicoatite-elbaite > Na-rich liddicoatite. Tourmaline from the exocontact ranges from Na-rich uvite > Ca-rich dravite > dravite-elbaite > Ca-rich Mg-bearing elbaite > liddicoatite-elbaite.
   The intermediate elbaite-schorl-dravite from unit A and schorl-elbaite-dravite from unit B and the exocontact is characterized by low Fe, moderate Ti, and high Ca and F contents. The dravite-elbaite from the exocontact is characterized by low Fe, Mn, Ti, Ca and F contents. The intermediate elbaite-schorl-dravite and elbaite-dravite solid-solutions crystallized as a result of mixing of (Ca, Mg)-rich fluids from the dolomite-calcite marble host-rock and exsolved (Na, Al, Li, F, B)-rich pegmatitic fluids. The factors controlling formation of elbaite-dravite in rocks may be summarized as follows: high activities of Li, Mg, Al and B, high Li/Mg ratio in the parent medium, acidic conditions with pH<-6, and lack of holmquistite. Consequently, elbaite-dravite solid-solutions should occur in highly contaminated elbaite-subtypr pegmatites penetrating marble and in holmquistite-free contact aureoles around complex LCT pegmatites
Přispěvatel
    Česká geologická služba
Kód přispěvatele
    ČGS (UNM)
Zdrojový formát
    U
Datum vložení
    16. 4. 2008
Datum importu
    8. 8. 2012